This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
The caraway plant, a native of Europe.
Carvacrol is a product of the essential oil of caraway, which is obtained from the seeds of the plant. Caraway - carum - seeds are of a light yellow color, with a pleasant aromatic smell, and a sweetish, warm, spicy taste. They are stomachic and carminative, and are occasionally used in flatulent colic, as a corrective of other medicines. The volatile oil of caraway is most employed in doses of gtt. j to gtt. x. Carvacrol is obtained by treating the oil of caraway with iodine, and washing the product with potassa, when it is mixed with carvene, which is one of the liquid oils of caraway. Carvacrol is also found among the products of the action of iodine on camphor. When pure, it is a colorless, viscid oil, lighter than water, in which it is nearly insoluble. Its odor is like that of creasote, and its taste is persistent, strong and acrid.
In dental practice, carvacrol has been employed as a substitute for creasote, carbolic acid and glycerole of thymol, in the treatment of odontalgia, sensitive dentine, alveolar abscess, and as an antiseptic in the pulp canals of teeth; also as a gargle in inflamed and ulcerated conditions of the mucous membrane of the mouth, tonsilitis, etc. Combined with water, in the proportion of 3 drops to the ounce, it forms an efficient gargle in stomatitis, tonsilitis, etc.; the strength of the solution may be increased, when a more powerful action is required. It is also employed with advantage in sensitive cavities of the teeth, in operating with the dental engine, to lessen the pain from friction of the instrument. As an application in odontalgia, from an exposed and irritable pulp, it affords almost instantaneous relief. It is claimed for carvacrol, that it is not so liable to cause inflammation as creasote; especially when it is applied through the pulp canals.
When employed to obtund the sensitiveness of dentine, it is necessary to confine it in the cavity of the tooth for a few days, by means of a temporary filling of zinc preparation, as it readily dissolves Hill's Stopping and gutta percha. When it is used in the form of an injection in alveolar abscess, a sharp, burning sensation is experienced as soon as it reaches the seat of the affection, when the crown cavity of the tooth should be immediately closed.
In patients of a scrofulous diathesis, it is necessary to exercise care in the use of carvacrol. When applied to cavities before the introduction of the filling, and to exposed pulps, it is introduced on a pellet of cotton.